According to Thompson, that lack of mobile spending amounts to a $20 billion gap and a budding crisis for news and entertainment companies that rely on ad revenue to do business.

Thompson says there are two primary reasons for the failure of mobile ads -- one technological and one cultural.

1. Mobile ad tracking is "dumb". The technology to track smartphone behavior is way behind traditional Internet tracking. Companies that invest in mobile ads therefore don't have a lot of data on who's clicking what, when, and why.

2. Mobile ads are an unexpected nuisance. Unlike TV commercials or magazine ad spreads, people aren't used to ads popping up while they play a mobile game or read articles in their news app. Mobile ads don't have the same cache as radio, tv, or print where you might actually stop what you are doing to hear or look at a commercial.

To hear more about the future of mobile ads, click on the audio player above.